How i can update my htc butterfly s through my lappy???

[AC Question]

I m currently using 4.2.2 In HTC butterfly s.When I checked software update its show me 4.4.2 .& then I started to download...when the download finish I start to install this update but it's not working....I tried three times but every time its show me an error...

So can u tell me how I can update my HTC butterfly s manually???